A budget will help you answer these questions and is absolutely essential in managing your personal finances.

Create a budget by writing down your expenses to find out where your money is going. Pull out your credit card bills and bank statements from past years as guides to your spending habits. Then estimate how much your new bills will be. Be sure to include expenses for entertainment, clothing and any other major expense category that you may encounter now that you're living on your own. Include some money for savings. It may take several months to fine-tune your budget to match your exact spending habits.

Now estimate your monthly income. Don't include potential income -- only income you are sure to receive. For example, don't assume your parents will send you money if they have not agreed to do so.

Check your budgeted expenses against your income. Do you have more going out than you have coming in? If so, you need to cut expenses. Entertainment bills are easy to trim; fixed costs such as utilities and housing are harder. Keep trimming until you have enough to cover your expenses. If you get paid hourly at a job, determine whether you can work more hours each week. You'll have to balance learning and earning: but be careful not to let your grades slip because you're working too much.